Q7LZG2 (PA2T_OXYSC) Reviewed, UniProtKB/Swiss-Prot
Last modified
May 1, 2013.
Version 44.
History...
Clusters with 
Names·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize orderNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize orderNames and origin
| Protein names | Recommended name: Phospholipase A2 taicatoxin Short name=TCX Short name=svPLA2 EC=3.1.1.4 Alternative name(s): Phosphatidylcholine 2-acylhydrolase |
| Organism | Oxyuranus scutellatus scutellatus (Australian taipan) (Coastal taipan) |
| Taxonomic identifier | 8667 [NCBI] |
| Taxonomic lineage | Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Elapidae › Acanthophiinae › Oxyuranus ›  |
Protein attributes
| Sequence length | 27 AA. |
| Sequence status | Fragment. |
| Protein existence | Evidence at protein level |
General annotation (Comments)
| Function | Heterotrimer: blocks the voltage-dependent L-type calcium channels from the heart, and the small conductance calcium-activated potassium channels in the chromaffin cells and in the brain. Is very toxic to mice. Ref.1 Ref.2 Ref.3 Ref.4 Ref.5 Monomer: Snake venom phospholipase A2 (PLA2) that has neurotoxic activities. Voltage-dependently affects ionic currents in chick (Gallus domesticus) dorsal root ganglion cells. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Ref.1 Ref.2 Ref.3 Ref.4 Ref.5 |
| Catalytic activity | Phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate. |
| Cofactor | Binds 1 calcium ion By similarity. |
| Subunit structure | Heterotrimer composed of an alpha-neurotoxin-like peptide of 8 kDa (AC P0CJ35), this neurotoxic phospholipase of 16 kDa and a serine protease inhibitor of 7 kDa (AC B7S4N9) at an approximate stoichiometry of 1:1:4; non-covalently linked. Ref.2 |
| Subcellular location | |
| Tissue specificity | |
| Post-translational modification | Contains 7 disulfide bonds By similarity. |
| Toxic dose | LD50 of the monomer is 500 µg/kg to mice. Ref.1 Ref.2 LD50 of the heterotrimer is 50-100 µg/kg to mice. Ref.1 Ref.2 |
| Sequence similarities | Belongs to the phospholipase A2 family. Group I subfamily. |
Ontologies
| Keywords | |
|---|---|
| Biological process | Lipid degradation Lipid metabolism |
| Cellular component | Secreted |
| Ligand | Calcium Metal-binding |
| Molecular function | Hydrolase Ion channel impairing toxin Neurotoxin Potassium channel inhibitor Toxin |
| PTM | Disulfide bond |
| Technical term | Direct protein sequencing |
| Gene Ontology (GO) | |
| Biological_process | lipid catabolic process Inferred from electronic annotation. Source: UniProtKB-KW |
| Cellular_component | extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell |
| Molecular_function | metal ion binding Inferred from electronic annotation. Source: UniProtKB-KW phospholipase A2 activityInferred from electronic annotation. Source: EC potassium channel inhibitor activityInferred from electronic annotation. Source: UniProtKB-KW |
| Complete GO annotation... | |
Sequence annotation (Features)
Sequences
References
| [1] | "Anionic currents of chick sensory neurons are affected by a phospholipase A2 purified from the venom of the taipan snake." Possani L.D., Mochca-Morales J., Amezcua J., Martin B.M., Prestipino G., Nobile M. Biochim. Biophys. Acta 1134:210-216(1992) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, LETHAL DOSE. Tissue: Venom. |
| [2] | "Isolation and physiological characterization of taicatoxin, a complex toxin with specific effects on calcium channels." Possani L.D., Martin B.M., Yatani A., Mochca-Morales J., Zamudio F.Z., Gurrola G.B., Brown A.M. Toxicon 30:1343-1364(1992) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION, SUBUNIT, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, LETHAL DOSE. Tissue: Venom. |
| [3] | "Effect of TaiCatoxin (TCX) on the electrophysiological, mechanical and biochemical characteristics of spontaneously beating ventricular cardiomyocytes." Fantini E., Athias P., Tirosh R., Pinson A. Mol. Cell. Biochem. 160:61-66(1996) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION. |
| [4] | "A novel small conductance Ca2+-activated K+ channel blocker from Oxyuranus scutellatus taipan venom. Re-evaluation of taicatoxin as a selective Ca2+ channel probe." Doorty K.B., Bevan S., Wadsworth J.D.F., Strong P.N. J. Biol. Chem. 272:19925-19930(1997) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION. |
| [5] | "Taicatoxin inhibits the calcium-dependent slow motility of mammalian outer hair cells." Su M.-C., Lee S.-Y., Tan C.-T., Su C.-C., Li S.-Y., Lin R.-H., Hung C.-C., Lin M.-J. Hear. Res. 203:172-179(2005) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION. |
Web resources
| Wikipedia Taicatoxin entry |
Cross-references
Sequence databases | |
|---|---|
| PIR | A34280. S21101. |
3D structure databases | |
| HSSP | HSSP built from PDB template 1AE7 based on UniProtKB P00608. |
| ModBase | Search... |
Protocols and materials databases | |
| StructuralBiologyKnowledgebase | Search... |
Family and domain databases | |
| InterPro | IPR016090. PLipase_A2_dom. [Graphical view] |
| Pfam | PF00068. Phospholip_A2_1. 1 hit. [Graphical view] |
| SUPFAM | SSF48619. PhospholipaseA2. 1 hit. |
| PROSITE | PS00119. PA2_ASP. Partial match. PS00118. PA2_HIS. Partial match. [Graphical view] |
| ProtoNet | Search... |
Entry information
| Entry name | PA2T_OXYSC | ||||||||
| Accession | Primary (citable) accession number: Q7LZG2 | ||||||||
| Entry history |
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| Entry status | Reviewed (UniProtKB/Swiss-Prot) | ||||||||
| Annotation program | Animal Toxin Annotation Program | ||||||||
| Annotation program | Chordata Protein Annotation Program | ||||||||
Relevant documents
| SIMILARITY comments Index of protein domains and families |